A method of treating glass light waveguide distal ends to obtain better return loss results was disclosed in commonly assigned U. S. patent application Ser. No. 07/898,653, now U.S. Pat. No. 5,226,101 the contents of which are incorporated herein by reference. A method was therein disclosed to mechanically polish the distal end of a glass waveguide thereafter to slightly melt the surface of said distal end to reduce return loss, the preferred means of inducing such melting being a laser.
While the method is described in said former patent achieved and proved results, potential problems remained. Melting the class at the surface of the light waveguide can alter the light waveguide surface geometry, and the degree of melting can be difficult to control. Due to the large amounts of energy needed, undesirable melting and the formation of holes in the light waveguide surface can occur. Another related problem is that of changes to the mode field diameter of the light waveguide due to dopant diffusion.
Therefore, it is believed that an improved method which retains the advantages of the former method while reducing or eliminating some of the disadvantages would be an improvement in the art.